Is there a good reason I see VARCHAR(255) used so often (as opposed to another length)?

Question

In multiple courses, books, and jobs, I have seen text fields defined as VARCHAR(255) as kind of the default for \"shortish\" text. Is there any good reason that a length o

Answer 1

Note: I found this question (varchar(255) v tinyblob v tinytext), which says that VARCHAR(n) requires n+1 bytes of storage for n<=255, n+2 bytes of storage for n>255. Is this the only reason? That seems kind of arbitrary, since you would only be saving two bytes compared to VARCHAR(256), and you could just as easily save another two bytes by declaring it VARCHAR(253).

No. you don't save two bytes by declaring 253. The implementation of the varchar is most likely a length counter and a variable length, nonterminated array. This means that if you store "hello" in a varchar(255) you will occupy 6 bytes: one byte for the length (the number 5) and 5 bytes for the five letters.